You don't have to get shaken mate, what really matters are the contents of their refutation...don't let their bragging intimidate you 😄...i read books trying to prove the case for a Trinity in the Godhead everyday, every authors writes in the conclusion that they've brought "undeniable" proof of a Triune Godhead in the Bible, does that mean i should believe them and get "shaken"? Of course not mate, we can't simply rely on the conclusion, it's their arguments that really matters and most of the time their arguments turns out to be weak or ridiculous quantum leaps...moral of the story is never judge a book or an article by it's conclusion, you have to look at the arguments first...